Trick or Kiss
by Linstead
Summary: Halloween. Erin and Jay go undercover to a party, to catch a drugdealer in the act. But when their cover is about to be blown, Erin has to improvise.


**I've co-written this story with Lara (lindsayshalstead on tumblr)**

She wasn't that big of a Halloween fan, dressing up in a costume and getting drunk with friends just because it was the 31st of October. That was basically what this holiday was about on her age.

Tonight she didn't have to worry about what she'd do on Halloween, because she actually had to work. Undercover. On a Halloween party. Dressed up, as _Catwoman._Okay, she'd picked her own outfit because there was no way in hell she was showing up at this party as the typical nurse, those were a dime a dozen. Besides, Jay would laugh at her for all eternity if she showed up as a nurse.

Slightly self-aware of the tight jumpsuit she was wearing and the way her body looked in it, she made her way towards the entrance of the club. The mask would keep her face hidden enough so the perp they were after wouldn't recognize her, but the high heels wouldn't be easy to run in. Thank God they had back up outside.

The moment she entered the bar, she scanned the room looking for her partner. And there he was, at the bar like he'd promised her. He was standing with his back towards her, so there was no way he could've noticed her, but Erin definitely recognized him.

A small smile crept up on her lips and for a moment she just stood there, looking at him, admiring his tall posture, his broad shoulders and those fine arms… Erin would lie if she said she didn't find him attractive at all. Jay Halstead was a fine, fine man, there was no doubt about that. Even if he was dressed as a cop, an outfit she'd seen him in a million times before, he was _really_ hot.

She took a deep breath and maneuvered through the crowd of dressed up people (a lot of nurses, how predictable) to the bar. Carefully she put her hand on Jay's arm and when he turned around and recognized her, she almost saw his jaw drop. Good.

"Really, Jay? A cop? So creative."

He seemed to get a grip on himself again and laughed a bit. "Unlike others, I didn't want to spend any money on this gig," he told her, grinning.

"Oh shut up, I look amazing and you know it. You'd rather see me in _this_than in anything else, just admit it."

Of course Erin looked incredible, Jay thought to himself. A part of him wished they were actually here together because they could be, not because of some undercover mission. "Wow, the cat claws are out already? You might want to save that for later tonight." Jay replied.

Erin's eyebrows perched up and even though it was dark she could've sworn Jay was blushing.

He cleared his throat, "I mean for tonight, when we catch the suspe-Dan Morrison."

Erin laughed and patted him on the shoulder when she said, "Oh I know exactly what you meant Jay. I just like teasing you."

They both sat on the bar. Each of them scanning the area, their eyes wide open for the suspect. They had to be extra careful, because if Dan saw them this whole thing could go wrong. Voight had made it crystal clear that today he'd be behind bars.

A girl dressed up as vampire approached Jay and sat next to him, a bit too close to him.

The girl kept her eyes at Jay and said, "Officer, I think you should arrest me. I've been a very very bad girl."

This caught Jay's attention, though all he did was force a smile. It wasn't that he minded her, she was pretty, but... _she's not Erin_ a voice in his head mumbled.

The girl got the message loud and clear and moved away.

Erin felt a pang of jealousy and anger. She wasn't the only girl starring at Jay. This made her even madder. Jay wasn't hers to feel like this, but she couldn't help it.

She sighed.

Unable to control her emotions Erin shook her head and laughed a bitter laugh, "Gotta love Halloween."

Jay noticed. "Jealous much?" he asked, with a grin so wide Erin wanted to smack and kiss him at the same time.

"No, you w-" but something caught Erin's attention before she could finish. She spotted Dan walking right towards them.

She stood up so fast, that Jay stared at her in alarm, "Hey what's wrong?"

She had to think quick, because Dan was approaching them. She couldn't let him see them. They didn't even have anything to cuff him for even if they wanted to blow their cover. Just as Jay was about to turn his face around, Erin grabbed his hand and forced him against the wall in a corner near the bar.

"If I can't tell you, I'll just show you." and she pressed her lips against his.

And suddenly the music wasn't so loud, the people weren't there anymore, it was just her and Jay. An explosion of fire spread through her veins. She'd never even felt anything like this. This kiss spoke the words that Erin couldn't tell Jay.

Jay was too shocked to process what was happening, but he kissed her back. It was hard but soft, passionate but sweet. She grabbed his shirt, eager to close every inch of distance between them. He wrapped his arms around her, not wanting to let her go. This was everything to him. He was crazy about her and the more he tried to push away his feelings for her, the stronger they came back.

She had no idea how long their kiss lasted. It could've been a couple of minutes, but to her it felt like an eternity and she didn't want it to stop. But it had to stop, she knew that too. They were on the job and they had to catch the perp before he got away. This was only… only a way to protect their cover.

Eventually she pulled back, out of breath but with a warm and fuzzy feeling in her stomach. For the last couple of weeks she'd thought about how it would be, kissing Jay. But she never could've imagined that it would like _this._Every vein in her body screamed for more and she had to keep herself from kissing him again.

Instead, she buried her face in his neck and let go of his shirt, to softly put her hand on his firm chest.

"Is he gone?" she blurted out, while she tried to keep her voice down in case he was anywhere near them.

"What? Who?" She could hear the confusion in Jay's voice and instantly she knew she'd made a mistake. Oh, yes, she'd absolutely wanted to kiss Jay and it was everything she'd hoped it'd be and even more, but now… now everything would be different between them, she knew that too.

"The suspect," her voice nothing more than a whisper.

"The suspect? Yeah, he's a couple feet away talking to some girls."

Now that the coast was clear, Erin pulled back and looked up at Jay for the first time since she'd kissed him. God, he was so beautiful, with his bright blue eyes and those soft pink lips. All she wanted to do was kiss him again, touch him, hold him. But she couldn't.

"This was just… a cover, Jay." _No, it wasn't. It was more than that. Way more. I want you._

"Just… just a cover?" Jay shot back, his voice a mix of anger and hurt. The look on his face was one she'd never forget. As if she'd just punched him in the gut.

"Don't tell me you didn't _feel_that!" he almost shouted, obviously confused by the whole situation.

Erin swallowed and shook her head. "Of course I felt it, Jay. And I'm doing my best to not kiss you again, because that's all I can think about. But we can't. It's as simple as that. We can't and you know it. Besides, we're on a job."

"Then why-" He couldn't even finish his sentence, cause he'd spotted something. Someone, to be exact. Dan Morrison, their suspect.

"We gotta go, we gotta go now. He's dealing. This might be the only chance we get tonight," he said, as if he'd suddenly forgotten all about their kiss and heated argument.

Erin nodded, backed away a few passes and then turned around, walking towards the suspect, followed by Jay who pulled his gun out of his holster.

"Dan Morrison? You're under arrest for dealing illegal drugs to minors," Erin began, as soon as they approached him. But as she suspected, Morrison had no interest in going with them willingly. He shoved one of the girls out of his way, right into Erins arms and he ran. Right towards the backexit where Ruzek and Olinsky would be waiting to catch him as soon he went through the door.

"Sorry," she said to the girl who was getting back on her feet, "you're all lucky you didn't buy anything from him yet, otherwise you'd be under arrest as well."

The three girls looked at her, startled by what just happened, but scooted away as soon as they realized she was dead serious.

"Come on, let's go get that guy so we can leave this place," Jay mumbled, eager to get out of this place and head home.

"Sure."

Without saying another word, she managed to find a way through the partying people, and got to the exit. As soon as she opened the door, she saw Ruzek pressing Morrison to his car, cuffing him in the process.

"Ah, look who's there! It's Kitty Cat!"

"You don't wanna piss off a cat, Ruzek," Jay said, before Erin could even respond to their colleague.

"So are you guys gonna keep on partying? You're here anyways. Al and I can finish this one up."

"I don't-" Erin started, but she was cut off by Jay.

"No, I'm heading back to the precinct. As a matter of fact, can I hitch a ride?"

"Eh, sure. Why not." Ruzek put Morrison on the backseat of the car and slammed the door shut. "How about you, Kitty Cat? You want a ride as well?"

Erin rolled her eyes and shook her head. "Thanks but no thanks. I've parked my car a few blocks away. I'll just head home immediately. Seems like you guys can manage this all by yourself. You don't need my supervision anymore."

She spotted Alvin walking towards her, "Can I catch a ride home?"

"Sure, Al why not?" The second she entered her car she felt as though she was about to break down. The kiss still lingered between her lips. Millions of thoughts ran across her mind, what was going to happen between her and Jay, would they just move on and act as if the kiss never happened?

"Rough night, Kid?" Alvin asked her.

She ran her hand through her hair, she felt so anxious "You have no idea."

A look of concern painted across his face. "You want to talk about it?"

She decided that it would be so much easier to just let it out, plus it was Al. She trusted him with her life. "I kissed Jay, okay. Our cover was about to be blown, so I went for it. Or at least I'm trying to convince myself that it was just for the cover and nothing more.."

"And did Jay know it was just for the cover?"

She shook her head, unable to make eye contact with him. She knew she'd ruined things with Jay and worse of all: she couldn't tell Voight about it.

Alvin put his hand on her back, trying to reassure her. "You and Jay will work it out, just like you always do and everything will go back to normal."

"But Al, what if I don't want _normal_? Erin snapped, "I don't know how long I can do this, pretend like I don't have feelings for Jay!" Her heart was racing, just_ talking_ about Jay.

He stared at her intently, "Just because you and Jay can't be together now, doesn't mean you never will be. The heart wants want the heart wants and no one, not even Voight can control that." Alvin stated.

This made Erin relax a bit. _He's right,_ she thought to herself. Now wan't forever and someday, someday her and Jay would break the barriers and obstacles between each other and give it try.

She smiled, grateful for this little talk, and hugged Alvin. "Thank you."

"Things will be okay. Don't you worry. And if you ever need anything else, someone to talk to you know I'm here for you."

"I know."


End file.
